Juan Carlos Linares

Universidad Pablo de Olavide | UPO · Department of Physical, Chemical and Natural Systems

This paper explores the potential of machine learning in predicting Basal Area Increment (BAI) for the species Abies spectabilis, a commonly used metric for measuring tree growth. Machine learning algorithms are used to analyze environmental factors, biotic responses, growth, and their interactions to obtain accurate predictions of BAI under differ...

Severe droughts limit tree growth and forest productivity worldwide, a phenomenon which is expected to aggravate over the next decades. However, how drought intensity and climatic conditions before and after drought events modulate tree growth resilience remains unclear, especially when considering the range-wide phenotypic variability of a tree sp...

Context West Mediterranean relict firs (Abies pinsapo Boiss. and Abies marocana Trab.) are closely related species threatened by global change. Government authorities in Morocco and Spain have established protected conservation areas around remaining fir groves but concerns linger regarding their effectiveness in light of emerging global environmen...

Circum-Mediterranean firs are considered among the most drought-sensitive species to climate change. Understanding the genetic basis of trees’ adaptive capacity and intra-specific variability to drought avoidance is mandatory to define conservation measures, thus potentially preventing their extinction. We focus here on Abies pinsapo and Abies maro...

Ongoing climatic change is threatening the survival of drought-sensitive tree species, such as silver fir (Abies alba). Drought-induced dieback had been previously explored in this conifer, although the role played by tree-level genetic diversity and its relationship with growth patterns and soil microsite conditions remained elusive. We used doubl...

Assessing tree growth patterns and deviations from expected climate baselines across wide environmental gradients is fundamental to determine forest vulnerability to drought. This need is particularly compelling for the southernmost limit of the tree species distribution where hot droughts often trigger forest dieback processes. This is the case of...

Introduction: Understanding the adaptive capacity to current climate change of drought-sensitive tree species is mandatory, given their limited prospect of migration and adaptation as long-lived, sessile organisms. Knowledge about the molecular and eco-physiological mechanisms that control drought resilience is thus key, since water shortage appea...

The frequency and intensity of drought events are increasing worldwide, challenging the adaptive capacity of several tree species. Here, we evaluate tree growth patterns and climate sensitivity to precipitation, temperature, and drought in the relict Moroccan fir Abies marocana. We selected two study sites, formerly stated as harboring contrasting...

Acute and early symptoms of forest dieback linked to climate warming and drought episodes have been reported for relict Abies pinsapo Boiss. fir forests from Southern Spain, particularly at their lower ecotone. Satellite, orthoimages, and field data were used to assess forest decline, tree mortality, and gap formation and recolonization in the lowe...

Climate change challenges the adaptive capacity of several forest tree species in the face of increasing drought and rising temperatures. Therefore, understanding the mechanistic connections between genetic diversity and drought resilience is highly valuable for conserving drought-sensitive forests. Nonetheless, the post-drought recovery in trees f...

Local differentiation at distribution limits may influence species' adaptive capacity to environmental changes. However, drivers, such gene flow and local selection, are still poorly understood. We focus on the role played by range limits in mountain forests to test the hypothesis that relict tree populations are subjected to genetic differentiatio...

Rear‐edge populations at the xeric distribution limit of tree species are particularly vulnerable to forest dieback triggered by drought. This is the case of silver fir (Abies alba) forests located in the southwestern of Europe. While silver fir drought‐induced dieback patterns have been previously explored, information on the role played by nutrit...

Tree‐ring data has been widely used to inform about tree growth responses to drought at the individual scale, but less is known about how tree growth sensitivity to drought scales up driving changes in forest dynamics. Here, we related tree‐ring growth chronologies and stand‐level forest changes in basal area from two independent datasets to test i...

Understanding spatially-explicit interactions between co-existing tree species provides valuable information about the trade-offs between facilitation and competition driving species coexistence and forest dynamics. Here, we analyzed the fine scale spatial pattern of Moroccan fir (Abies marocana) and Cedrus atlantica (Cedrus atlantica) in a mixed f...

Forest tree species are highly vulnerable to the effects of climate change. As sessile organisms with long generation times, their adaptation to a local changing environment may rely on epigenetic modifications when allele frequencies are not able to shift fast enough. However, the current lack of knowledge on this field is remarkable, due to many...

Tree plantations have been proposed as suitable carbon sinks to mitigate climate change. Drought may reduce their carbon uptake, increasing their vulnerability to stress and affecting their growth recovery and resilience. We investigated the recent growth rates and responses to the climate and drought in eight Atlas cedar (Cedrus atlantica) plantat...

Droughts chronically alter resource availability in forest ecosystems. The increased frequency and severity of such extreme climate events challenge the acclimation potential of tree species especially across the drought-prone Mediterranean region. Pinus nigra is a widely distributed tree species in the Mediterranean region and considered vulnerabl...

Current climate change constitutes a challenge for the survival of several drought-sensitive forests. The study of the genetic basis of adaptation offers a suitable way to understand how tree species may respond to future climatic conditions, as well as to design suitable conservation and management strategies. Here, we focus on selected genetic si...

The magnitude of drought impact in forest ecosystems depends on which group of trees are more severely affected; greater mortality of smaller trees can modulate the trajectories of succession, while the mortality of larger trees can disproportionately offset the ecosystem’s carbon balance. Several studies have documented a greater vulnerability of...

Forests are being impacted by climate and land-use changes which have altered their productivity and growth. Understanding how tree growth responds to climate in natural and planted stands may provide valuable information to prepare management in sight of climate change. Plantations are expected to show higher sensitivity to climate and lower post-...

Plant transpiration links physiological responses of vegetation to water supply and demand with hydrological, energy, and carbon budgets at the land–atmosphere interface. However, despite being the main land evaporative flux at the global scale, transpiration and its response to environmental drivers are currently not well constrained by observatio...

Drought negative effects on forest ecosystems are projected to increase under global warming all over the world. On this context, forest management can be an effective option for reducing drought impacts and increasing tree growth stability to extreme drought events. Here, we aim to evaluate black pine (Pinus nigra subsp. salzmannii) growth respons...

Current climate change in the Mediterranean basin is associated to increasing frequency and intensity of droughts. This climate dryness entails a serious impact on drought-sensitive forests , several of them considered as hot spots of biodiversity. Adaptive management, as experimental thinning for stand structural diversity enhancement, may increas...

Climate warming is expected to positively alter upward and poleward treelines which are controlled by low temperature and a short growing season. Despite the importance of treelines as a bioassay of climate change, a global field assessment and posterior forecasting of tree growth at annual scales is lacking. Using annually resolved tree‐ring data...

Resumen: Los pinsapares de Abies pinsapo son una de las formaciones boscosas más originales de la península ibérica. A pesar de la singularidad de estos ecosistemas, hasta el momento ningún análisis de microfósiles polínicos había sido emprendido en aquellos territorios donde esta especie, en peligro de extinción, aún pervive. Con este trabajo se p...

Significance Forests are experiencing growing risks of drought-induced mortality in a warming world. Yet, ecosystem dynamics following drought mortality remain unknown, representing a major limitation to our understanding of the ecological consequences of climate change. We provide an emerging picture of postdrought ecological trajectories based on...

Plant transpiration links physiological responses of vegetation to water supply and demand with hydrological,energy and carbon budgets at the land-atmosphere interface. However, despite being the main land evaporative flux at the global scale, transpiration and its response to environmental drivers are currently not well constrained by observations...

Understanding how climate warming and land-use changes determine the vulnerability of forests to drought is critical. However, we still lack: (i) robust quantifications of long-term growth changes during aridification processes, (ii) links between growth decline, changes in forest cover, stand structure and soil conditions, and (iii) forecasts of g...

Aim of study: Understanding small-scale patterns caused by stochastic factors or community interactions driving forest structure and diversity of Moroccan fir Abies marocana Trab. Area of study: Talassemtane fir forest, Talassemtane National Park, Rif Mountains, northern Morocco. Material and methods: Eight plots representative of the structural...

Extreme drought events are becoming increasingly frequent and extended, particularly in Mediterranean drought-prone regions. In this sense, atmospheric oscillations patterns, such as those represented by the North Atlantic Oscillation (NAO) index and the Westerly Index (WI) have been widely proven as reliable proxies of drought trends. Here, we use...

The negative impacts of drought on forest growth and productivity last for several years generating legacies, although the factors that determine why such legacies vary across sites and tree species remain unclear. We used an extensive network of tree‐ring width (RWI, ring‐width index) records of 16 tree species from 567 forests, and high‐resolutio...

Global climate change is expected to further raise the frequency and severity of extreme events, such as droughts. The effects of extreme droughts on trees are difficult to disentangle given the inherent complexity of drought events (frequency, severity, duration, and timing during the growing season). Besides, drought effects might be modulated by...

Increasing variability and uncertainty regarding future climate provide new challenges for the conservation of endangered tree species. For example, threat status can be impacted by genetic diversity, where forest trees show reduced geographic range size, isolated populations and fragmented distribution. We place the conservation insights of popula...

Severe droughts have the potential to reduce forest productivity and trigger tree mortality. Most trees face several drought events during their life and therefore resilience to dry conditions may be crucial to long-term survival. We assessed how growth resilience to severe droughts, including its components resistance and recovery, is related to t...

Plant traits—the morphological, anatomical, physiological, biochemical and phenological characteristics of plants—determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research sp...

Stand-level competition and local climate influence tree responses to increased drought at the regional scale. To evaluate stand density and elevation effects on tree carbon and water balances, we monitored seasonal changes in sap-flow density (SFD), gas exchange, xylem water potential, secondary growth, and non-structural carbohydrates (NSCs) in A...

This study links tree-ring growth and gross primary production for a variety of forest types under different environmental conditions across Spain. NOAA-AVHRR satellite imagery data were combined with dendrochronological records and climate data at a fine spatial resolution (1.21 km2) to analyze the interannual variability of tree-ring growth and v...

The effects of climate change on forest growth are not homogeneous across tree species distribution ranges because of inter-population variability and spatial heterogeneity. Although latitudinal and thermal gradients in growth patterns have been widely investigated, changes in these patterns along longitudinal gradients due to the different timing...

Wood constitutes the unique source of DNA in dead trees, but extraction of adequate quality DNA from dry wood is usually challenging. However, many different molecular studies require the use of such DNA. We have standardized and validated a modified CTAB protocol to isolate DNA from dry wood from Abies pinsapo and Cedrus atlantica species. Due to...

Current knowledge of climate change effects on forest ecology and species conservation should be linked to understanding of the past-time. Abies pinsapoforests constitute a model of an endangered ecosystem, highly vulnerable to ongoing warming, whose populations have been declining for centuries, while the drivers of this local depletion trend rema...

Tree mortality is a key driver of forest dynamics and its occurrence is projected to increase in the future due to climate change. Despite recent advances in our understanding of the physiological mechanisms leading to death, we still lack robust indicators of mortality risk that could be applied at the individual tree scale. Here, we build on a pr...

Treeline ecotones are considered early-warning monitors of the effects of climate warming on terrestrial ecosystems, but it is still unclear how tree growth at treeline will track the forecasted temperature rise in these cold environments. Here, we address this issue by analysing and projecting growth responses to climate on two different cold-limi...

Intraspecific variability in morphological and ecophysiological leaf traits might be theorized to be present in declining populations, since they seem to be exposed to stress and plasticity could be advantageous. Here we focused on declining Persian oaks (Quercus brantii Lindl. var. persica (Jaub and Spach) Zohary) in the Zagros Mountains of wester...

Drought is one of the key natural hazards impacting net primary production and tree growth in forest ecosystems. Nonetheless, tree species show different responses to drought events, which make it difficult to adopt fixed tools for monitoring drought impacts under contrasting environmental and climatic conditions. In this study, we assess the respo...

Drought is one of the key natural hazards impacting net primary production and tree growth in forest ecosystems. Nonetheless, tree species show different responses to drought events, which make it difficult to adopt fixed tools for monitoring drought impacts under contrasting environmental and climatic conditions. In this study, we assess the respo...

Drought is one of the key natural hazards impacting net primary production and tree growth in forest ecosystems. Nonetheless, tree species show different responses to drought events, which make it difficult to adopt fixed tools for monitoring drought impacts under contrasting environmental and climatic conditions. In this study, we assess the respo...

Pinus is a genus of conifers with a wide range of distribution, accounting for more than one hundred species. Among them, Pinus sylvestris L. is the most widely distributed pine, with more than 14,000 km from the Iberian Peninsula to the Siberian plain. Nowadays Scots pine has persisted in the Mediterranean region as relict populations, where it is...

Predicting the coping responses of tree species to climate change is, in many cases, limited by a lack of fundamental genetic insights, such as detailed knowledge of their genomes. Relict tree species may serve as models to assess the general mechanisms and patterns of forest tree responses to the changing climate and to explore the adaptive capaci...

Plants in Mediterranean mountains are particularly vulnerable to climatic change. In these environments, low temperature is combined with water shortage during summer, and as a result, the positive effect of global warming theoretically expanding the growing season length may be counterbalanced by rising drought stress. These circumstances may be e...

Aim We investigate the effects of the environmental and geographical processes driving growth resilience and recovery in response to drought in Mediterranean Pinus pinaster forests. We explicitly consider how intraspecific variability modulates growth resilience to drought. Location Western Mediterranean basin. Methods We analysed tree rings from...

Among the biodiversity components threatened by climate change, trees represent a main concern, since they constitute long­lived, sessile organisms, which theoretically lead to a slower evolution given that they mainly depend on current genetic variation to generate locally adaptive phenotypes. Even though tree populations often have great levels o...

Forecasted increase drought frequency and severity may drive worldwide declines in forest productivity. Species-level responses to a drier world are likely to be influenced by their functional traits. Here, we analyse forest resilience to drought using an extensive network of tree-ring width data and satellite imagery. We compiled proxies of forest...

Climate warming is predicted to intensify drought stress in forests by amplifying the severity and frequency of droughts. This drying trend will potentially trigger forest dieback, characterized by tree growth decline and mortality. In drought-prone Spain, forest decline is mainly attributed to severe water shortage. This inciting factor causes a l...

Understanding forest responses to the current climate change requires to investigate the effects of competition, buffering or enhancing process of forests decline. Here we attempt to place intra-specific competition in a climate change context, using as experimental system the drought-sensitive fir Abies pinsapo. We conducted a decade-long (2004–20...

Aim of study: Drought and stand structure are major and interconnected drivers of forest dynamics. Water shortage and tree-to-tree competition may interact under the current climate change scenario, increasing tree mortality. In this study, we aimed to investigate climate trends, site and stand structure effects on tree mortality, with the main hyp...

Significance Climate extremes are major drivers of long-term forest growth trends, but we still lack appropriate knowledge to anticipate their effects. Here, we apply a conceptual framework to assess the vulnerability of Circum-Mediterranean Abies refugia in response to climate warming, droughts, and heat waves. Using a tree-ring network and a proc...

Understanding forest responses to the current climate change requires to investigate the effects of competition, buffering or enhancing process of forests decline. Here we attempt to place intra-specific competition in a climate change context, using as experimental system the drought-sensitive fir Abies pinsapo. We conducted a decade-long (2004-20...

Climate extremes are expected to increase, which will affect oak forest ecosystems in Central European areas. Intensively managed forests, such as sessile oak stands, may alter their structure and function under a warming scenario. Here we analyse and project the climate-growth relationships of sessile oak (Quercus petraea) from high forests, origi...

Climate warming is predicted to intensify drought stress in forests by amplifying the severity and frequency of droughts. This drying trend will potentially trigger forest dieback, characterized by tree growth decline and mortality. In drought-prone Spain, forest decline is mainly attributed to severe water shortage. This inciting factor causes a l...

Forests worldwide have been recently affected by severe decline and mortality, while our understanding about forest decline across spatial scale is still limited. In this work we study how Quercus suber trees adjust their physiology, in terms of water use efficiency and secondary growth, to pathogen-induced oak decline at the whole-tree, local and...

Alpine treeline ecotones are considered early-warning monitors of the effects of climate change on terrestrial ecosystems, but it is still unclear how accurately treeline dynamics may track the expected temperature rises. Site-specific abiotic constraints, such as topography and demographic trends may make treelines less responsive to environmental...